Kodak TRI-X 400

created/modified 2018-01-11

Kodak TRI-X 400 B&W Film Profile/Review

This tech page is for Kodak Professional TRI-X 400 Film, or 400TX, which is it’s film code. This is a continuous-tone panchromatic black-and-white negative film for general outdoor and indoor photography. It is available in 35mm roll, 120 roll, 4×5, and 5×7 sheet form (as 320TXP). This film features high speed (ISO 400/27° in most developers), high sharpness, fine grain, and and high resolving power. 400TX has been around for a long time and Kodak has continuously released newer versions of the emulsion over that time period.

Development

There are many ways to develop 400TX. Following Kodak’s recommended development in their tech pub (F-4017, published Dec. 2016) is a good place to start if you’ve not developed this film before. If you send your film in here to Simple Film Lab, we develop 400TX with replenished Kodak XTOL with constant rotary agitation as standard practice. The standard development time is 8:30 at 68 degrees Fahrenheit. We use a 1:4 water:vinegar stop bath between development and fixing. We fix all BW films in Kodak Fixer.

Other developers and development schemes are available.

Exposure Guidance

There are many ways to meter and expose 400TX. If sending 400TX in to Simple Film Lab to process and scan, we recommend taking an incident light reading of the darkest part of the scene you want to retain details in and subtracting 2 stops of exposure from that reading. For example, if the darkest part of the scene that you want to retain detail in reads 1/125 shutter, f/4.0 at ISO 400, either set the shutter to 1/500 or close down the aperture to f/8.0, or a combination of the two to reduce the exposure by two stops.

If you don’t have a light meter, then set your camera exposure compensation to +1 stop, and that will generally result in an acceptable exposure for most situations once scanned in and density corrected.

If you want to add a stop of shadow information to the image, then place the darkest part of the image you want details in one stop down from the meter reading instead of two. 400TX has enough highlight exposure latitude that this is safe to do and still retain good highlight information for pretty much anything except the highest contrast scenes.

Characteristic Curve

Using Simple Film Lab, here’s the characteristic curve for 400TX overlaid with the standard 0.56 Contrast Index that is scanned in with:

400_tx_characteristic_curve

The scale along the bottom is exposure EVs, the scale along the left is the measured density as seen by the film scanner, meaning raw ADC values. The EV 0 mark is an 18% exposure card exposed correctly via an incident light reading with a Sekonic light meter through a T-Stop rated lens. Every dot along the curve is a full stop of light. The black curve is Contrast Index that the emulsion is digitized and linearized with, the green curve is the actual measured density values of the emulsion using the development described above.

Dynamic Range/Exposure Latitude

400TX has a good amount of dynamic range. Following the development practice described above and scanned in at CI 0.56, the film base plus fog starts to happen in EV -5 and is fully clear film base at the EV -6 mark. On the highlight side, with replenished XTOL it pretty much hits maximum density at +8 EV.

With the above information, in Adobe Lightroom, the visible dynamic range of an exposure is +7 EV to -6 EV. 400TX provides about 1 stop of under exposure and 1 full stop of over exposure protection while still maintaining acceptable black levels and full highlight retention for the full visible dynamic range in Adobe Lightroom. These over-under limits can be exceeded if you are OK with reduced performance at the extremes of the exposure scale. This equates to an exposure index range of EI 200 to 800.

Resolution/Grain

400TX has acceptable resolution for a 400 speed film. Looking at it’s tech sheet over at Kodak Alaris shows that it is at about 50 line pairs per mm of film at a 50% contrast response. In short, it’s nowhere near terrible, but it’s also nowhere near stellar. It’s right down the middle.

In terms of grain, there’s not much to be said here that hasn’t already been said pretty much everywhere else. It is Kodak TRI-X film, one of the most popular, classic, and legendary film emulsions ever made in the history of photographic film. If you’ve seen any black and white photos published in the mainstream media (magazines, newspapers, etc) over the last 40-50+ years, there’s a very high likelihood that you’ve been looking at TRI-X.

In 135 format, it’s grain is very present, but also very pleasant. In 120 roll medium format, it’s significantly reduced and that much more pleasant. In sheet form, it’s there if you look for it, but otherwise not really an issue. 400TX just has that look that is instantly familiar and recognizable. You know you’re looking at film, but there isn’t anything about what you’re looking at that would turn you off from film. It’s managed to hit that sweet spot of resolution, dynamic range, and graininess at just the right moment in photography that it took off and became the legend that it is today. If you haven’t shot any TRI-X, you should, just so you can say you did.

Sample Images

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Here’s a Flickr Album of images shot on 400TX. I’ll be adding new images as I shoot more.

Downloadable Sample DNG Files

As part of this tech sheet/film review I’m making a ZIP file available that contains some Adobe DNG files that are a sample of what you would receive if you sent your film into Simple Film Lab to process and scan. It’s relatively large, but if you want to see what you can get, worth a look. Download Here.